Four projects are outlined. 1) Studies of the impact of mass screening programs on persons discovered to be carriers or at risk for abnormal offspring, and a prospective study and evaluation of content, methods, and effectiveness of genetic counseling. 2) Continuation of a search for polymorphic variation among human ribosomal proteins. 3) Continuation of a study of the incidence of genetic disease among patients in pediatric services of the hospitals of Metropolitan Baltimore. 4) Continuation of a study of possible genetic origins of reading disability.